(Adapted from the Applicant?s Abstract) The Tissue and Cell Core Laboratory will provide support services to those projects in the Acute Lung Injury SCOR that require documentation of the functional studies; these studies will use both animal and clinical material obtained in the different Projects. The support services available include conventional light microscopy, electron microscopy, quantitative morphometry and molecular biology techniques. The quantitative morphometric techniques are available at both light microscopic and ultrastructural levels to provide quantitative correlation with the functional changes observed in other protocols. The molecular biology techniques include basic cloning, plasmid preparation and in situ hybridization. The Tissue and Cell Core Laboratory?s main interactions will be with Projects 1, 3, and 6. Project 1 will be studying patients with acute lung injury after pulmonary thromboendarterectomy. Project 3 addresses the role of the lung surfactant system in acute lung injury and what interventions may be beneficial. Project 6 focuses on the biology of PTHRP in acute lung injury. Tissues obtained from patients in the clinical studies either by lung biopsy during surgery or at autopsy will be processed by the Tissue and Cell Core Laboratory. These specimens will be reviewed by the Core Unit Leader confirming the pathologic diagnosis. Then, depending on the protocol, quantitative morphometric studies will be conducted to determine the extent of lung injury, e.g., acute damage, fibrosis, vascular injury and alterations in interstitial and air-vascular space rations. Qualitative assessments of the pulmonary inflammation present will be reported to correlate with the various experimental interventions. When appropriate, tissues will be prepared for immunohistochemistry. The services of the Tissue and Cell Core Laboratory will continue the ongoing collaborations of the present Acute Respiratory Failure SCOR at UCSD.